That is odd. Okay, this could be a few things that will have to be checked out by a Tech 2 qualified technician.
One - the cheaper solution. Your car and keys need a tech 2 to reprogram them
Two - the expensive solution. Your transponder is shot (broken) and needs replacing. That can be over a thousand dollars.
You did not say you can start the car or not. If you can start the car and it shows the message, then you just need reprogramming. If the car will not crank and start, then option 2 is more likely.
There are a few other reasons this could happen, but these are the most likely. Since the battery went dead I am hoping it is reason 1 that is your problem.
Good luck, let me know how it turns out.
One - the cheaper solution. Your car and keys need a tech 2 to reprogram them
Two - the expensive solution. Your transponder is shot (broken) and needs replacing. That can be over a thousand dollars.
You did not say you can start the car or not. If you can start the car and it shows the message, then you just need reprogramming. If the car will not crank and start, then option 2 is more likely.
There are a few other reasons this could happen, but these are the most likely. Since the battery went dead I am hoping it is reason 1 that is your problem.
Good luck, let me know how it turns out.